SOAP (Simple Object Access Protocol) is a simple protocol 
for exchange of information. It is based on XML and 
consists of three parts: a SOAP envelope (describing what's 
in the message and how to process it); a set of encoding 
rules, and a convention for representing RPCs (Remote 
Procedure Calls) and responses.
UDDI (Universal Description, Discovery, and Integration) is 
a specification designed to allow businesses of all sizes 
to benefit in the new digital economy. There is a UDDI 
registry, which is open to everybody. Membership is free 
and members can enter details about themselves and the 
services they provide. Searches can be performed by company 
name, specific service, or types of service. This allows 
companies providing or needing web services to discover 
each other, define how they interact over the Internet and 
share such information in a truly global and standardized 
fashion.
WSDL (Web Services Description Language) defines the XML 
grammar for describing services as collections of 
communication endpoints capable of exchanging messages. 
Companies can publish WSDLs for services they provide and 
others can access those services using the information in 
the WSDL. Links to WSDLs are usually offered in a company?s 
profile in the UDDI registry.